1. Field of the Invention
The present invention relates to hand tool technology and more particularly, to a tool bit adapter having a position-limit rod for hand tool.
2. Description of the Related Art
U.S. Pat. No. 6,637,755 discloses a chuck device for miniature tool bits, which includes a sleeve (20), a socket (10), a ball (14) received in between the sleeve (20) and each hole in the socket (10), and a pusher (30) mounted in the socket to stop against the balls. When installing a tool bit in the chuck device, insert the tool bit into the socket to push the pusher away from the balls. At this time, the sleeve can push the balls in direction toward the inside of the socket, forcing the balls into engagement with respective recesses in the miniature tool bit.
According to the aforesaid prior art technique, a C-ring (34) is mounted on the pusher (30); the socket provides a shoulder surface on the inside for stopping against the C-ring to keep the pusher in position. An elastic element 45 is received in the chamber 13 so that its first end is received in the second recess 32 of the pusher 30. Due to that the inner wall of the socket must be processed through a machining process, for example, turning process to provide the shoulder surface, the problems of increased cost and processing accuracy will be encountered. Further, the manufacturer can eliminate the lathe turning process by assembling two component parts to form the socket. However, assembling two component parts to form the socket relatively increases the cost and complicates the assembly process.